I've read that with high quality ammo the full chokes arn't needed.
Depending on the terrain your hunting such as a field I would personaly take all the chokes that came with the shotgun and see what combination works best.
My brother in law takes a weeks vaction to Dove hunt and travels to one of the many farming communitys here to hunt.
He use's a Browning Citori feather 12 ga. 26 barrels and carrys duplicate cylinder, modified and full chokes it all depends on where your at when you set up.
So if you don't have all the chokes then go buy them 2 of each kind and then shoot your gun to see what the different chokes do. You may even have a cylinder in one barrel and a modified in the other.
Where I live we have big wide right of ways and pastures, but it's hard to get permission to hunt in pastures or someone else has permission.
I discovered modified was best for me with a 28" barrel pump action.
I don't much care for 8 shot I use 7 1/2's and even 6's.
You say your gun has 30" barrels I would see how your modified choke does in it at the range but try them all.
Get to know that shotgun learn what shells it likes best and what the different chokes do. Just my two cents.